SYNTHESIS OF MAGNETIC AS(V)-IMPRINTED POLYMERS AND THEIR ADSORPTION PERFORMANCES FOR ARSENATE IN WATER SOLUTIONS

摘要

Three magnetic As(V)-imprinted polymers have been synthesized by surface-ion-imprinted technology with Fe_3O_4 nanoparticles as the support. The adsorption performances for arsenate in aqueous solutions using these polymers were investigated. The results showed that the difference of solvents and crosslinkers used in the experiments significantly affected the adsorption efficiency of the synthesized materials. It was found that the magnetic As(V)-imprinted polymer synthesized with ethanol as the solvent and without a crosslinker (IIP-eth) was most efficient for arsenate removal. The surface morphology and structure of this IIP-eth adsorbent was characterized by FT-IR, SEM, TEM and BET-N_2 adsorption technology. The results revealed that the IIP-eth was mainly consists of nanoparticles about 10nm with micropores. Its maximum adsorption capacity was 3.24mg/g at pH 4-5. The adsorption equilibrium can be reached within 10min and the adsorbent easily separated by applying an external magnetic field. The imprinting effect and the template-recognition behaviors of the As(V)-imprinted polymer was reflected by the selective adsorption for arsenate in the presence of other competing ions including Zn(II), Cd(II), Mn(II) and P(V). The desorption of arsenate was easy and the desorption rate was almost 100% when 2 mol/L HC1 was used as the eluent. It can be concluded that the synthesized IIP-eth is a promising absorbent for the selective removal of arsenic from water solutions.